package com.tianzj.boot.util;

import java.io.IOException;
import java.util.List;

import javax.servlet.http.HttpServletResponse;

import org.springframework.data.domain.Page;

import com.alibaba.fastjson.JSONObject;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.ObjectMapper;

public class JsonUtil {
	// 定义jackson对象
	private static final ObjectMapper MAPPER = new ObjectMapper();

	public static <T> String list2BootStrapJson(Page<T>  o){
		JSONObject obj=new JSONObject();
		obj.put("rows", o.getContent());
		obj.put("total",o.getTotalElements());
		return obj.toJSONString();
	}
	
	public static <T> String list2BootStrapJson(List<T>  o){
		JSONObject obj=new JSONObject();
		obj.put("rows", o);
		obj.put("total",o.size());
		return obj.toJSONString();
	}
	
    /**
     * 将对象转换成json字符串。
     * <p>Title: pojoToJson</p>
     * <p>Description: </p>
     * @param data
     * @return
     * @throws IOException
     */
    public static String objectToJson(Object data) throws IOException {
    	try {
			String string = MAPPER.writeValueAsString(data);
			return string;
		} catch (JsonProcessingException e) {
			e.printStackTrace();
		}
    	return null;
    }
    
    /**
     * 将json结果集转化为对象
     * 
     * @param jsonData json数据
     * @param clazz 对象中的object类型
     * @return
     */
    public static <T> T jsonToPojo(String jsonData, Class<T> beanType) {
        try {
            T t = MAPPER.readValue(jsonData, beanType);
            return t;
        } catch (Exception e) {
        	e.printStackTrace();
        }
        return null;
    }
    
    /**
     * 将json数据转换成pojo对象list
     * <p>Title: jsonToList</p>
     * <p>Description: </p>
     * @param jsonData
     * @param beanType
     * @return
     */
    public static <T>List<T> jsonToList(String jsonData, Class<T> beanType) {
    	JavaType javaType = MAPPER.getTypeFactory().constructParametricType(List.class, beanType);
    	try {
    		List<T> list = MAPPER.readValue(jsonData, javaType);
    		return list;
		} catch (Exception e) {
			e.printStackTrace();
		}
    	
    	return null;
    }

    public static String writeToHtml(HttpServletResponse response, String resultData){
        try {
            response.setContentType("application/json;charset=UTF-8");
            response.getWriter().write(resultData);
            response.getWriter().flush();
            response.getWriter().close();
        }catch (Exception e){
            e.printStackTrace();
        }
        return  null;
    }
    
}
